The present invention relates to a device for supplying cooler outside ambient air to a refrigerator enclosure when the outside air is at a lower temperature than the air temperature within the closure.
In conventional refrigerator apparatus, power operated means including a compressor, evaporator, and condenser are used for controlling the temperature within the cooled refrigerator compartment. Such power operated refrigeration equipment consumes an enormous amount of power even though many of the existing refrigeration units operate at temperatures above freezing. Thus, there has been a need for supplemental type systems which can be easily and inexpensively combined with conventional refrigerating equipment to reduce the work load on such equipment.
Several attempts have been made to combine a supplemental system with conventional refrigerating equipment. Some examples of the prior art supplemental systems are found in U.S. Pat. Nos. 2,855,839, 2,488,518, and 4,023,947. These prior art patents disclose that outside ambient air can be used to supplement the operation of the refrigeration equipment when the outside air temperature is equal to or below that required within the refrigeration enclosure.
A problem with the prior art constructions is that they are expensive and not easily incorporated into existing refrigeration equipment. Further, some of the supplemental supply systems are slow to react or reduce the flow of cold air into the enclosure which may cause damage to the goods. The rate of air flow from the outside must be controlled depending on the temperature difference between the outside ambient air and the temperature inside the enclosure. Thus, there has been a need for a supplemental supply unit which can be combined with an existing refrigeration enclosure to provide air flow into the enclosure when the outside air temperature is equal to or below the air temperature within the enclosure.
The dissadvantage of present supplemental systems for refrigeration equipment have resulted in the cold air supply system of the present invention which substantially reduces the work load on the refrigeration equipment and results in substantial savings in energy and expense.